NEW YORK — By his own admission, Bartlett Sher is not normally drawn to material like "The Bridges of Madison County," Robert James Waller's mega-bestselling 1992 novel.

The weepie about a brief but life-changing 1960s romance between an Italian war bride in rural Iowa and a peripatetic National Geographic photographer was adapted into a 1995 film starring Meryl Streep and Clint Eastwood. Now, under Sher's direction, it has been realized as a Broadway musical opening Feb. 20 at the Gerald Schoenfeld Theatre.

"It was not by my nature a story which I knew, or had read, or would read. The last romantic novel I think I read was 'Tess of the d'Urbervilles,'" Sher said, chuckling at the idea of Thomas Hardy's grim classic being a "romance."

"Whether I place the book as a great work of literature is a separate question from whether I see it as something which expresses a profound question within the American consciousness," he said.

And in that regard, he saw the potential in a story in which individual desires are pitted against familial duty and community obligation.

"I found it to be a really provocative and interesting thing," Sher said. "I'm sort of a Freudian about theater; it's always a struggle between freedom and security, between 'Do I stay where I am with my family because I love them or do I follow the thing that makes my heart feel the greatest?'

"That particular trauma," he added, "is the center of all human psychological endeavor."

With his shaggy salt-and-pepper hair and ensemble of dark jeans, sneakers and V-neck sweater, Sher, 54, looks like a New York City "cool dad" but over the course of a 30-year career has established himself as one of the most celebrated and versatile stage directors of his era, equally adept at musicals, straight plays and opera.

Sher's résumé, though eclectic, tends toward the highbrow. In the past five years alone, he's staged revivals of Clifford Odets' "Golden Boy" and (somewhat controversially) August Wilson's "Joe Turner's Come and Gone," directed operas new ("Two Boys" by Nico Muhly) and old (Gaetano Donizetti's "L'Elisir d'Amore") and been at the helm of a musical version of Pedro Almodóvar's film "Women on the Verge of a Nervous Breakdown" for Lincoln Center Theater, where he is resident director.

But Sher has also shown a flair for bittersweet tales on romance inflected with serious social themes — decidedly grown-up fare that is increasingly scarce in a Broadway dominated by broad comedies and jukebox shows. He won a Tony in 2008 for his revival of "South Pacific" and was nominated in 2005 for the lyrical "The Light in the Piazza," both of which starred Kelli O'Hara, who plays the lonely Francesca in "The Bridges of Madison County."

Known for breeding loyalty among his actors and crew, Sher was brought aboard the project about four years ago by O'Hara.

"She's a real friend and a real artist who I feel invested in, who inspires me and whose vocal and dramatic growth has been a real gift to me," Sher said. "I love her. So I said, 'Sure, let's try it.'"

Even more so than in Eastwood's film, the narrow world of Waller's 200-page novel has been expanded in the Broadway version. The book by Marsha Norman ("'night, Mother") fleshes out the back stories of Robert (played by Steven Pasquale in his Broadway musical debut) and especially Francesca.

He's a restless commitment-phobe, she's a woman who, desperate to escape the horrors of war-torn Naples, married Bud (Hunter Foster), a sweet but unsophisticated American soldier from Iowa. As a farmer's wife and the mother of two teenagers, she's long since sublimated her dreams and ambitions in favor of domestic stability.

The musical is particularly sympathetic to her plight and almost plays like a feminist fable — appropriate given its setting in 1965, Sher said. "Francesca is standing up at a point when women were beginning to move into a new role where they were really present and alive inside the culture and were making choices for themselves outside of the role of mother and wife."

The show's expansiveness is enhanced by music and lyrics by by Jason Robert Brown (a Tony winner for "Parade" in 1999). Like Sher, he hadn't read the book before becoming involved in the musical but was excited by the chance to do something romantic and weighty — to write what he calls "big music." Brown's score mixes lush, romantic strings evocative of Italy with decidedly American influences — blues, folk, country and early rock 'n' roll.

"He's created a pretty unbelievable hybrid that I don't know that a lot of people could pull off," said Pasquale. "There are two very different scores, one which is rural but really has a drive to it, and another which is very European and classical. It's its own language, which is really the reason to buy the ticket."

Brown put it a slightly different way: "The best way for me to think of it is it sounds like Iowa in 1965, as experienced by these people."

For a musical based on a renowned tear-jerker, "The Bridges of Madison County" is also surprisingly funny, with comic relief provided by Francesca and Bud's bickering teenagers, played by Caitlin Kinnunen and Derek Klena, and especially with the role of Marge (Cass Morgan), Francesca's nosy neighbor.

At first Marge appears to embody the familiar archetype of small-town busybody, tracking Francesca's affair with a pair of binoculars and swooning over the hunky Robert in a Patsy Cline-esque number, "Get Closer."

But her character ultimately surprises as perhaps the kindest in the show. Her moral transformation aligns with Sher's more optimistic view of so-called flyover country, which he likens to the work of author Alice Munro.

"We get a lot of raps as Americans for being small-minded, but in fact when you really drill down to the core of the culture, there's an enormous amount of compassion and forgiveness and support," Sher said. "Maybe the struggle in our culture now is for who gets to win, the ones who want to be moral and puritanical and dominating and rapacious capitalists, or the ones who want to be compassionate and connected and understanding ideas of community."

The show's exploration of community is manifest by townspeople who silently sit in chairs on the edge of the stage throughout much of the piece. "I think it is a Greek chorus," Sher said of the device. "What do the citizens of Thebes think about what's happening to Oedipus, or in this case, what do the citizens of Winterset, Iowa, feel about this relationship?"

"Bart understands very deeply the emotional life of a show. That's why for a show like this he's the perfect person to be directing," said Brown. "The look of the show reflects its emotional life."

The musical had a well-received tryout last summer in Williamstown, Mass., with Elena Shaddow playing Francesca. (O'Hara was in the late stages of pregnancy at the time and unable to perform but had participated in the three years of workshopping that preceded it.)

Since then, Brown, Norman and Sher have continued to rework the piece, trimming it by about 15 minutes since its Williamstown run. On the afternoon of our interview, Sher had been rejiggering a pivotal sequence in the second act, one which required a "really tricky emotional build" that they'd nailed only twice.

"When you make new musicals, you have the great freedom and the great burden that it can be changed," he said wearily.

Often asked which medium he prefers to work in, Sher insists he loves his children equally, though each presents particular challenges. The pace and scale of opera is "like drinking water from a fire hose," while staging a play is "fundamentally harder because no rhythm is in place."

As a director in the world of theater and opera, Sher is comfortable in his role, closer to that of an interpreter than a creator. "But," he added, "I'm always in the gray area between."